Abstract
Fiber Reinforced Polymer (FRP) repair systems on pipe substrates have been used successfully for leak sealing and for reinforcement. Due to corrosion, mechanical damage, or both, some small defects such as pinholes, cracked welds and small punctures can be repaired by such composite repair systems. The repair method consists of the design of a circumferential composite wrap which is laid-up and bonded to the pipe substrate, in the field, where a defect exists or is expected to exist. The effectiveness of the composite repair system is highly dependent on the adhesive fracture toughness between the two substrates, pipe and composite. The interfacial fracture toughness through the use of small circular defects, known as “blisters”, has been characterized through the use of the “blister test”. In some cases a repair may not have proper surface preparation in the immediate defect area due to severe corrosion. However, proper surface preparation is available in areas slightly removed from the defect. The repair for this type of defect will create a large encapsulated blister. Although large, the general shape of the blister and its front can be easily controlled. This study analyzes one textile glass fiber/epoxy composite repair system. This paper presents the results of an investigation including theoretical analysis, full-scale experimentation, and analysis of results to better understand and design reliable methods to design effective repairs.
